Process of manufacturing crucible cast-steel



' of Crucible Cast-Steel; and I improved quality duced cost.-

I phosphoritic molt as aphosphate. The metal should then, '45

' UNITED-STATES PATENT l OFFICE,

JACOB REESE, or rIrTs Une, PENNSYLVANIA.

Paooess OF'MANUFACTUBING CRUCIBLE CAST-STEEL,

SPECIFIG ATION forming part; of Letters Patent No.. 283,141Qdated August14, 1883.

' Application filedFebruaryA, 1882. (No specimens.)

To all whom, it may concern.-

Be itknown that-I, Jnoon Rnnsn, acitizen of the United States, residingat Pittsburg, in the county of Allegheny and State of Pennsylvania, haveinvented a certain new and useful Improvement in Processes for theManufacture do hereby declare the following to be a full, clear, andexact description thereof.

Crucible cast-steel has heretofore been man-' ufactured fromblister-steel or wrought-iron, or iron and steel scrap. The crucibles,or pots,

as they are called, are .made of German clay and plumbago, pounds ofscrap metal; H

The object of my inventionis to-produce an of crucible cast-steel at are- 'My invention consists in the hereinafter-described process forattaining-said object.

In the practice of myinvention I blow nonn iron with an air-blast in asilicious-lin'ed converter until the silicon and carbon are eliminated."The metalis then, mi.- nus the slag,.poured into crucibles which havebeen previously such-chemicals, flux, may be required for or man'ganesemetal as the. reduction of the grade of steel desired, Vighen the potsare thus filled the lids are. put on,;and they are placed in themelting-furnace and-subjected to the usual treatment afterinelting.-When' the'steel has thus been subjected to the dead melt, the pots arewithdrawn ,and the metal poured-into ingot-molds.

In thepractice of this invention, phoritic metal is used, he molten bedesiliconized when phosmetal may to an overblowfintil the phosphorusis'o'xidiiedto phosphoric acid and held in theslag minus thephosphoritic slag, be poured into hot crucibllesplaced in thefurnace-and subjected to the refining and dead-meltperiod, after whichwithdrawn and the metal the crucibles may be poured into ingot molds; orthe phosphoriticmet'al may be run direct into a basic-lined vessel andtherein blown until the silicon and carbon are eliminated, and-the blowthen conand generally hold about ninety heated, and having therein anddecarburized, as before described,- aud'then,-minus the silicious slag,-metal, but the met produce with such day from tinned, in the presence ofa highly basic slag, until the phosphorus" is oxidized, and thusremovedfrom the metal and held in the slag as apho'sphate. The desiliconized,decar'bu- 'rized, and dephosphorized metal thus made may then be pouredinto the hot crucibles and subjected to the but in either case toexclude both the silicious and phoritic slag from the crucibles.

The time required to produce a heat by this process will-,not exceed onehour, as the pots are hot and-the metal is in a highly fluid condition;'and, taking theoidinary-sized pots, in

great care should be the phostreatment before described; 7

taken which ninety pounds is the utmostthat can 11 charging them withmetal in a fluid state I am enabledto put into each crucible one h'undred and twenty-five pounds.'

In the practice of my invention the chemimowfbe packed in them, by mymethod of cals, flux, and manganesic additions are c'arefully weighedand kept in cans ready for use, and immediately after the crucible isemptied. the contents of one of these cans is placed in it and themolten metal then poured in until the vessel is sufficiently filled.

The charged pot is then placedin the furnace and treated asbeforedescribed, In no case shouldthe pots be permitted to get colduntil they are worn out, and in case the molten metal is not ready for afresh charge the pots should bereturned to the furnace immediately afterpouring, in order that they may be kept in a hot condition, ready forthe next charge, as thecooling and reheating of crucibles is verydestructive to them, and often cause the pots to crack and permit theircontents to flow out into the furnace, which is not only a loss of potsand 1 getting into the 'gasports obstructs the proper working of thefurnace. v f In the practice of :my invention, in works where thirtyfive-pot melting-furnaces are used, I employ a five-ton converter, andby making two blows .per hour I am enabled to' a plant two hundred nettons of crucible cast-steel ingots per day of twenty hours, leavingample time for repairs, while in the present crucible practice not morethan thirty five net tons can-be produced per fivethirty-potmelting-furnaces.

In thepractice of the old process of producing crucible ("aststecl, bycharging scrap and pieces of steel while cold into the puts, aconsitflerable amount of oxides and dirt is admixed with tho-charge,aslhe metal is all more or less oxidized on its surface, and carrieswith it a considerable amount of dirt. (then the metal is melted it onlyiills the pot two thirds full. The oxides and dirt lloat upon thesurface of the metal, which, with the'lluxing materials, forms a:l'usible and. very destrnc tire slag, which decomposes the pot at theslag.

horizon, thus cutting a ring or annular groove around the inside of thepot about one-third the distance from the top of the pot to its bottom.In my process the dirt is entirely avoided, and by deoxidizing themolten metal previous to its being poured out of the convertor oxidesare also excluded from the cru 'eiblcs, and they are charged with pureiron in a liuid state, and thus the destruction of the pots from theaction ol'thc slag will liealnn'ist,

if not entirely, avoided.

By the old process, in which the metal is melted in the pots, it iscxcecdingl y costly to produce homogeneous steel, low in carbon, for

boiler-Mate, as it requires a very high and continuous temperature tomelt a charge which is principally of wroughtiron; but in my improvedprocess I melt castiron, which is easily fused, and convert it into'lluid dc- SiiCuIliZOd and decarbnrized iron, and by charging the potswith that quality I am on abled to produce soft or homogeneous steel ascheap as any other g ado.

The advantages of this invention are,lirst, the metal may thus be placedwithin the crucibles at less cost per ton than by the old method ofcharging cold material into cold pots; second, a series of pets maybecharged with a metal of absolute uniform quality; third, the cost offuel for melting and refining in the plil's will be reduced eightyiiveper cent, because 5.88 times the metal, with the smile fuel, will beproduced by my process as is now produced by the method oi charging coldmaterial into cold pots; fourtl'i, the cost 05' crucibles will bereduced fully fifty per cent, as they may be used double the numberot'heats, owmg tothe short't-ime they remain in the furnace, and byreason of keeping them con tinuously hot; lil'th, the cost of plant perton ol'ingots produced will be largely reduced, even alter taking intoconsideration the Bessemer additions; sixth, a better and more uniformquality ol'stccl can be produced, because a unie'sa, m i

.lbrmquality of metal is charged into the pots, and [or this reason auniform treatment can be given to it and a uniform duration of the deadmelt secured; seventh, scrap may be utilized to much better advantage,by the old practice the sc up must be sheared or. broken into smallpieces, so as to be closely packed in the pots, while in my improvedprocess the unsheared scrap may be thrown into the converter and thereinmelted inthe act ofblowing; eighth, by'excluding the dirt and oxidesfrom the crucible the life of the potis extended and a better quality ofsteel may be produced; ninth, by charging decarburized iron in a moltenstate into the crucible soft orhomogeneousstccl may be produced at nogreat er cost than that which is highly carburizetl.

I wish it distinctly understood that I do not in this application claimany part of the process or processes described by which the cast-iron isconverted in the Bessemer vessel as distinct and separate from itsfurther treatment, as set 'l'ort-h; but when such treat ing cruciblecast-steel, which consists, first, in

desili eonizing and decarb'urizing iron; second, in charging said molteniron into crucibles containing deoxidizing, fluxing, and steel-producingagents; and, third, in subjecting said iron, while contained in saidcrucibles, to a dead melt, substantiallyin the manner and for thepurposes described.

2. The process herein described for the pro duction of homogeneoussteel, which consists, essentially, first, in i lesilieonizing,decal-burizing, and dephosphorizi'ng eastiron; second, in charging themolten metal into previouslyheatcd crucibles containing deoxidiiing,fluxing, and recarburizing agents; and, third, in subjecting the metalto a dead melt, substantially in the manner and for the purposesdescribed.

J AGOB REESE.

Witnesses:

FRANK M. Rnnsn, NAT/FER REESE.

